Artificial denture.



Patented April 4, 1905.

PATENT OFFICE.

BENSON W. FORDYGE, OF BEDFORD, IOVA.

ARTIFICIAL DENTURE.

SPECIFICATION formingpart of Letters Patent No. 786,748, dated April 4, 1905.

Application filed June 4, 190%. Serial No. 211,183.

To all whom it may concern:

Be it known that I, BENSON W. FoaDYoE, a citizen of the United States, residing at Bedford, in the county of Taylor and State of lowa, have invented new and useful Improvements in Artificial Dentures, of which the following is a specification. Y

This invention relates to means for attaching tooth-crowns tonatural tooth-roots, and particularly to means of such character embodying an anchor-post fitted in the toothcanal and to which the crown is attached.

The object of the invention is to provide improved means for attaching artificial crowns to natural tooth-roots in such manner that when once the anchor-post is seated in the root-socket, which may be done by any means known in the art, a crown may be secured thereto and removed therefrom without destroying or causing the least injury to the anchor-post. The crown, notwithstanding the fact that it can be removed from the anchor-post, is held with great firmness and solidity thereon when placed in position on a tooth.

This attachment is applicable for use on incisor, bicuspid, and molar teeth with equal facility and rigidity. It may also be advantageously used in dental bridgework.

In the accompanying drawings, Figure 1 is a vertical sectional View through my improved tooth-crown in position on the root of a lower incisor tooth. Fig. 2 is a similar view of my invention showing a modified form of securing the artificial crown to the anchor-post. Fig. 8 is a perspective view of an anchor-post used in connection with the form of crown illustrated in Fig. 1. Fig.4 is a similar view of the anchor-post used with the modified form of my invention. Figs..5 and 6 are perspective views of two forms 1 of ferrules or sockets used in connection with my improved crown. Fig. 7 is a vertical sectional View illustrating my invention as applied to a bicuspid tooth. v

Similar numerals of reference indicate corresponding parts throughout the several Views.

The numeral 1 indicates a portion of an incisor tooth shaped at the top to fit the base of an artificial crown 2,- which is preferably made of porcelain. ,1 do not, however, confine myself to this particular material, as other substances well known in the art may be used.

,3 indicates a metal anchor-post, the lower portion of which'is cylindrical in form and adapted to be fixed in-a root-canal in any wellknown manner.

The projecting portion of the anchor-post is-in the form represented in The walls of of other form. If the opening 5 be greater in one direction than in the other, its longer axis should lie in a labiolingual direction or from before backward.

Shaped to the inner or lingual surface of an incisor or cuspid tooth and to the grindingsurface of a hicuspid or molar tooth is a "metal plateor backing 6, which assists materially in holding the crown in place on the natural root of a tooth.

, A ferrule or socket 7 is fitted snugly to the shape of the opening 5, but not secured there- 1n. the metal plate or backing 6 to the base of the tooth-crown or slightly beyond it, if neces- When in place, the socket 7 extends from sity demands, as in a short tooth, for instance.

The opening 5in the crown 2 illustrated in Fig. 1 is of rectangular form and narrower at the base than at the end next to the plate or backing 6, to which it is soldered or otherwise securely attached. When the socket 7 is placed in the opening 5 and the plate or backing 6, soldered thereto, is pushed toward the crown until it is firmly seated thereon, the socket will have passed through the hole 5, closely fitting it, until its smaller end has reached the base of the crown or in some cases passed beyond it.

To apply a crown oftheabove-described backing.

form on an incisor root, the tooth is first prepared and the anchor-post fastened therein in the usual manner, with its forked end spread and projecting from the root of the tooth. The socket is placed within the hole 'in the crown and the metal plate or backing pushed to place. The prongs 4: of the anchor-post are then pressed together, placed in the socket, and the crown pushed down until it is seated on the surface of the root prepared to receive it. As the crown passes to its seat tne prongs 4: will spring outwardly and bear against the inner sides of the socket, thereby holding" the crown lirmly in position.

The fastening means shown in 2 comprise an anchor-pin 8, squa in cross-section above the root and having a notch 91 cut in one side near its upper end. l The socket 10 is also made square to fit asq uare hole 5 in the crown 2. In this variety of socket the end soldered to the metal plate or backing 8 is independently closed at its end soldered to the plate or It may, however, be left open, as in socket 7, or the latter socket closed. A portion of the front side of the socket 10 is cut to form a spring 11, projected within the soeketand pointing, upwardly. The crown 2 is attached to the root by pushing the socket 10 in the crown 2 over the anchor-pin 8 until the spring 11 enters the notch 9 in the an chor-post, by which time the cr wn will be properly seated on the root The anchor-post may be plain or provided with locking devices, such as notches and projections, which interlock with projections and notches in the socket.

From the above it will be seen that thereis no fixed connection between the anchor-post and the metal plate or backing 6 and that a crown can be removed at anytime or when broken replaced by a new one. As the an- CllOIWpOSi] is in no way attached to other parts of the crown, it is therefore stronger, as it is not softened or annealed by heat to which other forms of posts known to me are subjected.

The principle of this invention may also be used in dental bridgework, and the porcelain in case oi breakage can be replaced without removing the abutments, thereby making the mechanism as perfect as it was originally.

Before applying: the crown to the anchorpost a sufiicient quantity of cement, gutt npercha, or similar material is placed within the socket 7 to iill the spare between the prongs 4: of the post and between said prongs and the plate 6, should there be any. When it becomes necessary to remove the crown, which, as a rule, is caused by breaking or split-ting of the porcelain body, the front of the crown is broken away so that access may be had to the socket 7, which is slitted, as well as the plate 6, when necessary to enable the operator to drill out or otherwise remove the coment or gutta-percha filling. The remaining: portion of the crown may then be witlnlrawn from the anchor-post and a new crown substituted.

Having thus described the invention, what is claimed as new is 1. An artificial denture comprising a crown having a longitmlinal opening therethrongh extending outwardlyfrom its base, a metal plate or backing adapted to lit closely against the inner or upper surface of said crown and close the opening therethrough, a tube or socket firmly attached to said metal plate or backing'and shaped to fit the openingin said crown, and an anchor-post secured to a toothroot, its. projecting end being: so formed as to bear against all sides of the socket when placed therein and be held in place by spring means.

2. An artificial denture, comprisinga crown having an opening thercthrough extending from its base, a metal plate or hacking adaptcd to lit closely against the inner or upper surface of said crown and cover said opening, a socket lirmly attached to said plate or backing and conforming to the shape oi the opening in said crown, and an anchor-post having one end provided with a spring-fork and adapted to enter said socket and be locked therein.

in testimony whereof I afiix my signature in presence oi two witness BENSON Vi". F0 ltl )YCE.

fl "itnesses:

Ensin U. l'iLAKlS'JONE, (:Pnonon M. Bonn. 

